IDENTIFICATION OF MINNESOTA AQUATIC INVASIVE:
Eurasian Watermilfoil (Myriophyllum spicatum)
SEARCH LOCATIONS In 3-12 feet of water in lakes or bays with soft sediment
SEARCH TIME May through September
SEARCH IMAGE Branching stems may/not form mats just below water
surface (flowers may extend above water) Feathery leaves
IDENTIFICATION CHECKLIST
Leaves have a central axis
12 or more leaflet pairs on leaf (hint: count the leaflets on one side of the axis)
OTHER HELPFUL NOTES Leaves hang limp
when out of water Leaflets at the ends of
the leaves tend to form a blunt tip—rather than tapered
Plants have a reddish hue
mat just below water surface
flower above water
surface
branching stems, feathery leaves
Feathery leaves leaf
central axis
1
16 2
leaflet
Northern watermilfoil Water marigold
Coontail
Bladderworts
?
Water marigold leaves have no central axis
Bladderworts have leaves with small sacs
Northern watermilfoil has less than 12 leaflet pairs
Coontail leaves have no central axis
? 8
Leaf
centra
l axis
3
LOOK-ALIKES with feathery leaves
© 2014 Regents of the University of Minnesota. All rights reserved. University of Minnesota Extension is an equal opportunity educator and employer.
7-25-2014
MN native MN native
MN native
MN native
Search image
Search image
MINNESOTA STATUS: Prohibited invasive species It is unlawful (a misdemeanor) to possess, import, purchase, transport, or introduce Eurasian watermilfoil except under a permit for disposal, control, research, or education. IF YOU FIND A NEW OCCURANCE OF EURASIAN WATERMILFOIL, contact your local MN DNR Name and contact information can be found at: http://www.dnr.state.mn.us/invasives/ais/contacts.html METHOD(S) OF REPRODUCTION Stem segments can root and grow into new plant (stems break from waves, boat propellers, harvesting) Underground stems (rhizomes) spread outward from original plant Seeds have poor germination VECTORS OF SPREAD Plants or stem fragments in/on boats, motors, live wells, bilges, boat trailers, other equipment STRATEGIES FOR RESTORING NATIVE PLANT COMMUNITY (Contact your local MN DNR for permit and specific details) 1) Ongoing Eurasian watermilfoil control, including chemical and mechanical treatments (biocontrols are be-
ing tested for potential release—weevils, midge and caddisfly ) 2) Allow native aquatic plant community to recover
RESOURCES Printed Czarapata, E.J. 2005, Invasive Plants of the Upper Midwest – an illustrated guide to their identification and
control. Madison: University of Wisconsin Press, 215 pp. Web Center for Invasive Species and Ecosystem Health: http://www.invasive.org
MN Dept. of Natural Resources: http://www.dnr.state.mn.us/invasives/index_aquatic.html and http://files.dnr.state.mn.us/aboutdnr/reports/legislative/2012_invasive_species_annual_report_final.pdf
INFORMATION ON MINNESOTA AQUATIC INVASIVE:
Eurasian Watermilfoil (Myriophyllum spicatum)
Weevils on milfiol